Thermoelectric devices can be configured to both create power and pump heat, making such devices widely applicable in a variety of commercial, consumer, and military applications. For example, thermoelectrics have been suggested as power sources for remote sensors that can extract power for their operation based on, for example, existing thermal gradients such as a temperature difference between the air and the sea. Thermoelectric devices have other desirable features for many applications. For example, thermoelectric devices can operate with no moving parts and thus can operate silently. These and other uses would be significantly enhanced with higher performing thermoelectric devices. While advances in thermoelectric technology have been made, improved thermoelectric materials are necessary for many practical applications.